Not working correctly in IE10 with STL file

```
What steps will reproduce the problem?
1. IE10 W7Pro (VS2010 not required)
2. STL file
3. jsc3d 0.9.8

What is the expected output? What do you see instead?
STL file should be loaded but get
Java script error regarding "overrideMimeType"
Works OK in Firefox etc

Please provide any additional information below.

Seems to give error on "overrideMimeType"
in the following javascript function - error skipped if tested first but then
no STL file loaded - error line is remarked out below

JSC3D.StlLoader.prototype.loadFromUrl = function(urlName) {
var self = this;
var xhr = new XMLHttpRequest;
xhr.open('GET', urlName, true);

if (!!xhr.overrideMimeType) xhr.overrideMimeType('text/plain; charset=x-user-defined');
/*xhr.overrideMimeType('text/plain; charset=x-user-defined');
*/
```

Original issue reported on code.google.com by `hutchin...@gmail.com` on 21 May 2013 at 11:56

Start at JSC3D.StlLoader.prototype.loadFromUrl and reproduce the IE10 failure with the listed STL file and jsc3d 0.9.8 setup. Check the XMLHttpRequest overrideMimeType handling; done means the STL loads in IE10 without the reported JavaScript error while existing browser behavior remains intact.

Written by the indexing model from the issue text.